nfsd: check d_can_lookup in fh_verify of directories
Create and other nfsd ops generally assume we can call lookup_one_len on
inodes with S_IFDIR set. Al says that this assumption isn't true in
general, though it should be for the filesystem objects nfsd sees.
Add a check just to make sure our assumption isn't violated.
Remove a couple checks for i_op->lookup in create code.
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c
index 27250e2..cfe7500 100644
--- a/fs/nfsd/nfsfh.c
+++ b/fs/nfsd/nfsfh.c
@@ -59,14 +59,20 @@
* the write call).
*/
static inline __be32
-nfsd_mode_check(struct svc_rqst *rqstp, umode_t mode, umode_t requested)
+nfsd_mode_check(struct svc_rqst *rqstp, struct dentry *dentry,
+ umode_t requested)
{
- mode &= S_IFMT;
+ umode_t mode = d_inode(dentry)->i_mode & S_IFMT;
if (requested == 0) /* the caller doesn't care */
return nfs_ok;
- if (mode == requested)
+ if (mode == requested) {
+ if (mode == S_IFDIR && !d_can_lookup(dentry)) {
+ WARN_ON_ONCE(1);
+ return nfserr_notdir;
+ }
return nfs_ok;
+ }
/*
* v4 has an error more specific than err_notdir which we should
* return in preference to err_notdir:
@@ -340,7 +346,7 @@
if (error)
goto out;
- error = nfsd_mode_check(rqstp, d_inode(dentry)->i_mode, type);
+ error = nfsd_mode_check(rqstp, dentry, type);
if (error)
goto out;
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index fba8e7e..cf14e39 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1169,9 +1169,6 @@
dentry = fhp->fh_dentry;
dirp = d_inode(dentry);
- err = nfserr_notdir;
- if (!dirp->i_op->lookup)
- goto out;
/*
* Check whether the response file handle has been verified yet.
* If it has, the parent directory should already be locked.
@@ -1310,12 +1307,6 @@
dentry = fhp->fh_dentry;
dirp = d_inode(dentry);
- /* Get all the sanity checks out of the way before
- * we lock the parent. */
- err = nfserr_notdir;
- if (!dirp->i_op->lookup)
- goto out;
-
host_err = fh_want_write(fhp);
if (host_err)
goto out_nfserr;